PURPOSE: To supply the quantity of heat for drying an internal organ, etc., in a system and to save thermal energy to be consumed by burning the organ produced from a steam indirect heating type dryer, recovering the steam from the combustion heat, and using the steam for drying.

CONSTITUTION: The internal organ of a scallop in a raw material hopper 1, for example, becomes a water content of 55-80% via a boiler, and is fed to a dryer 3. A dried article from the dryer 3 is self-burned in an incinerating furnace 4. Exhaust gas from the burned organ becomes a temperature of 750-800°C via a deodorizing furnace 5 to be completely deodorized. The exhaust gas at 750-800°C is passed through a waste heat boiler 6 to become 300°C, steam is generated corresponding to the quantity of heat, and fed to the dryer 3. Steam drain is recovered, returned to a feed water tank 7, and the quantity of heat of the drain is also recovered. Thus, the quantity of heat for drying the organ, etc., can be recovered in a system, thereby saving thermal energy to be consumed.